Go to 4KFree.com
(Don’t worry, it’s free)
Download Free Flash Transitions. Yes, free. No cost. No watermarks. No nonsense. Simply FREE effects.
Import the effect into your favorite video editor. These effects work in any editing app that can read a quicktime file. (Apple Final Cut Pro X, Apple Final Cut Pro 7, Adobe Premiere, Avid, Media 100, Resolve, Vegas, etc.)
Drag the Flash on top of your video.
Change the Blend Mode.
Go to 4KFree.com Download your favorite effect. Import the effect. Drag it on top of your video. Change the blend mode.